1.
Phytochemistry
; 65(23): 3159-65, 2004 Dec.
Artigo
em Inglês
| MEDLINE
| ID: mdl-15541746
RESUMO
Three new triterpenes, synthesized by a Bolivian strain of the green microalga Botryococcus braunii, were isolated and their chemical structures determined by 1D and 2D NMR, and mass spectrometry. These compounds are tri-, di-, and mono-methylsqualenes, co-occurring with the previously identified tetramethylsqualene and some C(30)-C(32) botryococcenes. In this strain, methylated squalenes constitute up to 24% of the total hydrocarbons and 4.5% of the dry biomass. The results of a pulse-chase experiment with L-[Me-(13)C] methionine provide evidence for the origin of these compounds via methylation of squalene at positions 3, 7, 18 and 22.